For what you are asking, the BMW based suspension really doesn't mean any thing. Unless BDR has tested your setup on your tires and come up with a recomendation (did you ask them) then you are asking for some one else's personal preference. BFG has this formula:
(Vehicle Weight in lb/100) + 2 psi at heavier end + 2 psi all around if suspension and alignment are stock.
Example: 2800 pound car
(3000/100) = 28 psi
Add 2 psi all around = 30 psi
Add 2 psi to heavy end = 32 psi at rear
Many find that high, put plug in yours numbers and see what you think. Play with them up and down a few pounds and try again. Have fun!
